High temperature, molten electrolyte, electrochemical cells have been shown to be an efficient method of producing energy particularly when the fuel source is hydrogen gas. Carbon as a fuel source in electrochemical cells has been explored. Efficiencies of various carbon sources have been calculated based on half-cell data and have consistently been low, e.g., 50% or less.
Aspects of the invention include a high temperature, molten electrolyte electrochemical cell comprising ash-free, turbostratic carbon particles.
Another aspect of the invention includes a high temperature, molten electrolyte, electrochemical cell for directly converting a carbon fuel to electrical energy, the electrochemical cell comprising a cathode compartment having an oxygen-containing gas and a molten electrolyte; an anode compartment having a slurry comprising the molten electrolyte and carbon particles entrained in the molten electrolyte; and an electron insulating, ion conducting, porous ceramic separator between the cathode compartment and the anode compartment.
Another aspect of the invention includes a high temperature, molten electrolyte electrochemical cell for directly converting a carbon fuel to electrical energy, the electrochemical cell comprising a cathode compartment formed by a housing comprising non-porous, inert material having a gas inlet and outlet, an oxygen-containing gas, a molten electrolyte, and a cathode current collector; an anode compartment having an inlet, an anode current collector, and a slurry comprising the molten electrolyte and carbon particles entrained in the molten electrolyte; and an electron insulating, ion conducting, porous ceramic separator between the cathode compartment and the anode compartment, the porous ceramic separator capable of allowing transport of ions produced in the cathode compartment to the slurry.
Another aspect of the invention includes a method for producing electrical energy, the method comprising the steps of heating an electrochemical cell containing a carbon fuel entrained in an electrolyte to an operating temperature; producing carbonate ions by bringing an oxygen-containing gas in contact with a cathode current collector wetted with molten carbonate; transporting the carbonate ions through a porous ceramic separator to an anode current collector; reacting the carbonate ions with the carbon fuel; and collecting the electrical energy produced through the anode current collector.